Little tool, big results. Johnson's 12" metal combination square gives you the accuracy and precision you need for every job and was designed to be durable for a lifetime of use. Its stainless steel blade has graduations of 1/8", 1/16" and 1/32" that are permanently stamped so you'll never worry about them fading or wearing. Similarly, the durable acrylic vial, heavy-duty cast zinc head with a black, chip-resistant e-coating finish and hardened screw-in scriber that won't fall out helps this combo square withstand even the roughest job site abuse. It was also designed with maximum accuracy in mind - its square head is CNC machined for greater accuracy and the Auto-Lock™ blade assembly makes it easier to accurately line up your tool for use.